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CVE-2015-1821

Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a...

6.5 MediumFix available

CVE-2015-1821 is a medium vulnerability (CVSS 6.5) in Tuxfamily Chrony, published April 12, 2015. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.41%, the 88th percentile. Fixed in chrony 1.30-2.

Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a denial of service (chronyd crash) or possibly execute arbitrary code by configuring the (1) NTP or (2) cmdmon access with a subnet size that is indivisible by four and an address with a nonzero bit in the subnet remainder.

Exploit likelihood

3.41%Down 0.5 points since Feb 4, 2022
90%50%10%1%

What each source reports

NVD Score used 6.5

Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a denial of service (chronyd crash) or possibly execute arbitrary code by configuring the (1) NTP or (2) cmdmon access with a subnet size that is indivisible by four and an address with a nonzero bit in the subnet remainder.

Record
CVE-2015-1821
CVSS 2.0
6.5 MediumAV:N/AC:L/Au:S/C:P/I:P/A:P
Weakness
CWE-119
Updated
2026-11-02
CVE List No score

Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a denial of service (chronyd crash) or possibly execute arbitrary code by configuring the (1) NTP or (2) cmdmon access with a subnet size that is indivisible by four and an address with a nonzero bit in the subnet remainder.

Record
CVE-2015-1821
Updated
2026-11-02
EUVDEUVD-2015-1941 No score

Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a denial of service (chronyd crash) or possibly execute arbitrary code by configuring the (1) NTP or (2) cmdmon access with a subnet size that is indivisible by four and an address with a nonzero bit in the subnet remainder.

Record
EUVD-2015-1941
Updated
2026-11-03
GitHub AdvisoriesGHSA-cm73-xw9w-xqmm No score

Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a...

Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a denial of service (chronyd crash) or possibly execute arbitrary code by configuring the (1) NTP or (2) cmdmon access with a subnet size that is indivisible by four and an address with a nonzero bit in the subnet remainder.

Record
GHSA-cm73-xw9w-xqmm
Weakness
CWE-119
Updated
2026-11-02
OSV No score

Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a denial of service (chronyd crash) or possibly execute arbitrary code by configuring the (1) NTP or (2) cmdmon access with a subnet size that is indivisible by four and an address with a nonzero bit in the subnet remainder.

Record
CVE-2015-1821
Updated
2026-11-02
OSVDEBIAN-CVE-2015-1821 No score

Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a denial of service (chronyd crash) or possibly execute arbitrary code by configuring the (1) NTP or (2) cmdmon access with a subnet size that is indivisible by four and an address with a nonzero bit in the subnet remainder.

Record
DEBIAN-CVE-2015-1821
Updated
2026-11-02
OSVMGASA-2015-0163 No score

Updated chrony packages fix security vulnerabilities

Updated chrony package fixes security vulnerabilities:

Using particular address/subnet pairs when configuring access control would cause an invalid memory write. This could allow attackers to cause a denial of service (crash) or execute arbitrary code (CVE-2015-1821).

When allocating memory to save unacknowledged replies to authenticated command requests, a pointer would be left uninitialized, which could trigger an invalid memory write. This could allow attackers to cause a denial of service (crash) or execute arbitrary code (CVE-2015-1822).

When peering with other NTP hosts using authenticated symmetric association, the internal state variables would be updated before the MAC of the NTP messages was validated. This could allow a remote attacker to cause a denial of service by impeding synchronization between NTP peers (CVE-2015-1853).

Record
MGASA-2015-0163
Updated
2026-11-02
OSVUBUNTU-CVE-2015-1821 No score

Heap-based buffer overflow in chrony before 1.31.1 allows remote authenticated users to cause a denial of service (chronyd crash) or possibly execute arbitrary code by configuring the (1) NTP or (2) cmdmon access with a subnet size that is indivisible by four and an address with a nonzero bit in the subnet remainder.

Record
UBUNTU-CVE-2015-1821
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
chrony
Debian:12
before 1.30-2
1.30-2
chrony
Debian:13
before 1.30-2
1.30-2
chrony
Debian:14
before 1.30-2
1.30-2
chrony
Debian:6.0
before 1.24-3+squeeze2, plus listed versions
1.24-31.24-3+squeeze1
1.24-3+squeeze2
chrony
Debian:7
before 1.24-3.1+deb7u3, plus listed versions
1.24-3.1+deb7u11.24-3.1+deb7u2
1.24-3.1+deb7u3
chrony
Mageia:4
before 1.29.1-1.1.mga4
1.29.1-1.1.mga4
chrony
Red Hat:enterprise_linux:7::client
before 0:2.1.1-1.el7
0:2.1.1-1.el7
chrony-debuginfo
Red Hat:enterprise_linux:7::client
before 0:2.1.1-1.el7
0:2.1.1-1.el7
chrony
Red Hat:enterprise_linux:7::computenode
before 0:2.1.1-1.el7
0:2.1.1-1.el7
chrony-debuginfo
Red Hat:enterprise_linux:7::computenode
before 0:2.1.1-1.el7
0:2.1.1-1.el7
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Affected packages
PackageAffectedFixed
chrony
Red Hat:enterprise_linux:7::server
before 0:2.1.1-1.el7
0:2.1.1-1.el7
chrony-debuginfo
Red Hat:enterprise_linux:7::server
before 0:2.1.1-1.el7
0:2.1.1-1.el7
chrony
Red Hat:enterprise_linux:7::workstation
before 0:2.1.1-1.el7
0:2.1.1-1.el7
chrony-debuginfo
Red Hat:enterprise_linux:7::workstation
before 0:2.1.1-1.el7
0:2.1.1-1.el7
chrony
Ubuntu:14.04:LTS
before 1.29-1ubuntu0.1, plus listed versions
1.26-41.29-1
1.29-1ubuntu0.1

History

History
WhenChangedSources
2026-11-03aliasesEUVD
2026-11-02createdCVE List, GitHub Advisories, NVD, OSV

References

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